The Louisiana Democrat. [volume] (Alexandria, La.) 1845-1918, 1887-10-26
POPULAR SCIENCE.

POPULAR SCIENCE. |
It is not to be assumed that the English
lifts" are the equals of The American ele-
yators, but the use OF compressed air for op-
Grating them is sufficiently general there TO
indicate that it may, to an extent, take the
London and other ports the elevators IN the
big warehouses are operated almost eXcau-
siYely by compressed air, which. when ex-
haustad into various rooms OF the Du!ldlngs.
serves to yentilate and purify them. Another
advantage claimed for compressed air Is lis
great elasticity. The elevators run more
smoothly and stop and start less abruptly,
and are less liable to bEeakage when a quick
stop is made than when water is used.
Prof. W.. A. Anthony, speaking In the
American Association. Section OF Physics, on
Tie Importance of teaching. physical science
in the public. schools. said that proper sclen-
iific instruction in the primary schools would
teach children to avoid the mistake OF at
tempting the impossible. While grammar
be Taught b, reading, not by rules; flle fseog-
raphy, after teaching the form of the earth,
should be used only as book OF reference;
and the commercial departments OF arltilne-
children in their earliest experiences have 10
do with heat, light, sound, movement and
magnetism. Physics should be taught by
calling attention to familiar facts, and then
explaining them.-PoDular Science Monthly.
Mr.. Yiilon, engineer and chemist, after
five months experimentation with various
tannins in order to asce. tain which is most
effective III preventing the lncrustahon OF
boilers, states in the CTT0aig4e JndGSt'Iete
that the best results are given by lsumeN by
menosepalnm, a species OF dock that grows
plentifully in sandy soils in a large territory
owl NOT of in Q>,Ia
there northward over large portion OF
Western Texas. The Dubious root Called
'canaigre'p is the part used. The roots are
produced in clusters weighing several pounds.
with gum, starch and ligAeous matter.
liquid extract is made from them. which IS
purified with acetate of zinc in order to re-
move the gum and resin, and brown liquid
is obtsined marking 200 b. OF this five
grams {seyenty-ire grains} per hydrotinet-
1.ic degree of water and per cubic meter (264
gallonD are used.
An Austrian paper clairls that the first
lightning-rod was constructed by monk in
Bohemia. !. The apparatus which he set up in
the garden OF the curate. OF Pfendltz i'll
aa5a was raa Of p9e pg
branches. and terminating i'll as many me
tallic boyeB filed with iron ore and closed
by u lockwood cover, trayersed by, twenty
seven sharp iron points which riunged at
united to. the earth by large chain. The
enemies of Diwisch, Jealous Of. his success at
the Court OF Vienna, excited the peasants OF
the locality against him, and under the pre-
text that it was the cause OF the great drouth
they made him take down the lightning-rod
which he had utilized for six gears, What is
most curious is the form OF this first light
ning-rod, which was of multiple points Like
the one which 81. Melseu afterward invented.
A remarkable secret has just been revealed
after burial in the sea for mere than thirty
boat. built by Wilhelm Bauer, was sunk in
the harbor of kiel, where j. remained in
fortyfeet of water until lately discovered in,
the course OF dredging operations. The ca
rioas craft has been raised, and its naechan-
exposed TO view. The boat was made of
sbeeS-ifon, and WIS twentj-six feet long, ten
feet deep and six feet vide. The driving was
effected by means of three .bladee screw
worked By two large wheels, each wheel
turned hya MIN tresding on projections on
it's periphery. The bow extended upward in
a peculiarly shaped head provided with bulls
eyes closed by thick glass. Sinking and
raising were effected by admitting and pump
ing out water: The boat was designed for
placing torT1edloes under hostile yessels, aud
was successfully. tested, but WAS, unfortu-
nately, crushed by the pressure of the wa
ter at "a depth OF thirty Feet. 1t will beTee
constructed and preserved as the first VEN
ture iusrbmaaiiie warfare.
Prof. r. W. Raymond gave to Mrs. Ellen
Richards, of the MassUchNsettcs Institute OF
Technology. some somewhat broken speci-
mems OF eriogonum ovaliTolium which he
had exhibited to the institute as plant
growing in silver ore localities. Most of
them had rose-colored blossoms. On
NIrs. Richards has since reported the
interesting results of chemical analysis In
consequence Of the views above suggested rs
to the possible Significance Of color, the pink
lowered plants were treated separately.
The specimens were cleaned as completely
as possible from earth: but this separation
could not be made perfect, because the
earth adhered i'll particles to the woolly
leaves, as was. proved by the subsequent
detection in the ash of scales Of bronze
mica. The plants lost 6 per cent of
moisture On drying at 1909 G., and yielded
IL per cent of ash, of which 40 per cent
WIS soluble in acid. The presence of arsenic
was qualitatiyely proved in the plants, and
the earth was found to contsln Il considerable
In the plants with yellow flowers arsenic Vas
not found.
A paper by Alfred H. Cowles is soon to be
issued by the United States Naval Institute
on aluminium bronze for heavy. guns, which
M R aH SSised on ne tae r ns cawes
asserts that by either tie Rodnsn or o..
Deame process of casting guns can be
made of this alloy that viii have q
much higher tensile strength and ductil-
ines; that ii would b. impossihia to burst u
gun cast from, this alloy with four
times the powder now used in the
''.buiit-up'' steel gan, and, finally. that the
plants required for. producing aluminium
bronze and casting guns therefrom would
great an outlay as it is proposed 80 invest in
pants for the construction of bu;lt-up guns,
while not one,,qnarteT. Of the time viii be
necessary to build the aluminium plant
matgd that guns can be cast from
aluminium bronze at 20 per cent less
than the forged guns OF steel, while so per
| cen5of this cost will be capital stored away
in the metal of the gun. which metal can be
re,nelted and used over an indefinite number
of times. The leading inetalureists and ord
nanee experts OF the United States, Great
Britain, France, Belgium and Germany viii
be invited to discuss the paper. u
The experiments of MN. Coulter and Mas
csit, extended by AitkiIa, have demonstrated
that in 8 perfectly moist air no formation OF
tnre be lowered, SO long as the air is abso-
lutely free. from dust, and that the more
air, sufficiently, moist, may be charged
with such foreign particles, the more
a sufficient lowering of the temperature or
pressure of the air. Let filtered and com.
pletely moist air in a glass ball have its pres
SUI e Diminished, then only i. few particles of
fog viii reveal themselves to the most careful
inspection, even under the powerful light OF
an electric lamp-particles OF fog which,
moreover, yield not the slightest eoloietI
ina &c. Ii there be now admitted into this
filtered air 3 few cubic miiimetres Of ordin-
airy house air. which, always contain. numer-
Gus notes or particles Of Dust a very fine,
siiyery transparent fog will at once form it.
SELF of such slight density that, even in the
Gaze OF considerable area of it, the trans.
parency of the atmosphere would be
but very slightly affected. II at the
image OF the sun, Or reflected light oi
an electric lamp, be viewed through it, the
IMAGE viii be neen surrounded bT an in.